The most commonly used electrolyte salt for lithium inorganic oxyhalide electrochemical cells as for example lithium sulfuryl chloride (SO.sub.2 Cl.sub.2) and thionyl chloride (SOCl.sub.2) cells has been LiAlCl.sub.4. However, cell capacity is normally limited by accumulation of lithium chloride at the carbon cathode. Chloride ions are formed at the cathode during reduction of the solvent and lithium ions are present in the LiAlCl.sub.4 salt as well as being formed by oxidation of the lithium anode. Thus, lithium chloride is formed as a cell discharge product in sulfuryl chloride and thionyl chloride.
In sulfuryl chloride, the reaction can be represented as: EQU 2Li.fwdarw.2Li.sup.+ +2e.sup.- EQU 2e.sup.- +SO.sub.2 Cl.sub.2 .fwdarw.SO.sub.2 +2Cl.sup.-
The net result is the formation of 2LiCl+SO.sub.2.
In thionyl chloride, the reaction can be represented as: EQU 4Li.sub.- .fwdarw.4Li.sup.+ +4e.sup.- EQU 4e.sup.- +2SOCl.sub.2 .fwdarw.SO.sub.2 +S+4Cl.sup.-
The net result is the formation of 4LiCl+SO.sub.2 +S.
The low solubility of LiCl in these solvents results in LiCl precipitating and clogging the pores and surface of the carbon cathode. Cathode activity is reduced, leading to cell failure. Although at low constant current discharge rates LiCl is fairly evenly distributed throughout the cathode allowing a relatively long capacity, at high discharge rates the LiCl tends to deposit mainly on the cathode surface. The interior of the cathode is not utilized, the surface is quickly coated with LiCl, and capacity is greatly decreased.